The present invention is directed to a toy track vehicle with optical sensors, and a method for controlling the vehicle on a printed track. Specifically, this invention comprises a toy track vehicle having optical sensors
Toy track vehicles have been a mainstay of children""s toy chests for the past century. Such tracked devices have varied widely. Simple track vehicles include mechanically guided, electrically driven trains such as the trains manufactured by LIONEL and other similar toy manufacturing companies. There are also more sophisticated devices that operate via remote or voice control and have bells and whistles controlled by sensors embedded in the track
More recently, LEGO introduced a form of trackless vehicle having a built-in programmer that communicates with a personal computer (PC) using an infrared link. This trackless vehicle also has touch and optical sensors allowing the vehicle to execute a series of preprogrammed, motor driven motions that can be conditionally changed by sensor inputs.
Toy vehicles found in the prior art include U.S. Pat. No 3,849,931 to Gulley, Jr. that describes a method of guiding a toy vehicle with a light beam. U.S. Pat. No. 4,086,724 to McCaslin that describes a toy vehicle with a steering mechanism that is responsive to acoustic signals, and U.S. Pat. No. 5,630,743 to Shi that describes the use of a specific type of CdS photoresistors for sensing reflected light from a track. The steering of the Shi vehicle is accomplished using a complex mechanical arrangement comprising a set of worm gears that drive the vertical axle, which in turn causes the wheel assembly to turn, thereby turning the car. There is no provision for illumination; this vehicle appears to depend on ambient light only.
What is needed in the art is an inexpensive, simple toy vehicle for use on a printed track that is optically controlled, and a method for controlling the toy vehicle on a printed track. This method needs to be an inexpensive method for guiding a vehicle without the need for mechanical constraints.
Accordingly, the present invention overcomes the disadvantages of the prior art by providing an inexpensive, simple toy track vehicle that is optically controlled for use on a printed track, and a method for controlling the toy vehicle on a printed track.
In a first aspect, the present invention provides a toy track vehicle having at least one optical sensor that is used on a printed track. The toy track vehicle additionally has at least two wheels driven by at least one motor and a light source. The light source may be ambient light, light from an LED, or other light known in the art. The toy track vehicle has a smaller turning radius than can be achieved with rails or other tracking devices.
In a further aspect, the present invention relates to a method for guiding a toy track vehicle on a printed track. The toy track vehicle has wheels and also has at least one optical sensor for sensing track position. The track is printed on paper and is preferably produced by a computer program. The track further includes control symbols that keep the vehicle on track. The control symbols can also initiate other actions, such as reversing direction, accelerating, stopping, making sounds and turning on lights. The computer program that designs and prints the track can produce an essentially unlimited number of variations of track shape and control symbol locations so as to provide an ever changing sequence by simply modifying the layout on the computer and printing out a new control track. Alternatively, the track can be drawn by hand by the user rather than printed on a computer printer and preprinted or hand drawn control symbols can be placed by hand along the track.
In a further aspect, the present invention provides a method for controlling a toy track vehicle on a printed track and eliminates the slow and limited process of mechanically modifying interconnecting track segments. The track is infinitely changeable by simply modifying the program on a personal computer to produce a new track shape and printing out the track on ordinary paper. Alternatively, the user can draw the track by hand on paper or other contrasting surface and draw new tracks as desired.
In another embodiment, the track surface may be folded for compact storage. Additionally, this method provides a form of tracking that allows the toy vehicle to have a much smaller turning radius than can be achieved with rails or other mechanical tracking devices so as to allow more varied track patterns.
In a further embodiment, the present invention provides a method for placing recognizable symbols at points along the track to initiate actions such as reversing, stopping, accelerating and producing sounds and turning on lights.
These and other objects and features of the invention will be apparent from the detailed description set forth below.